A credible source close to Nigeria’s President Goodluck Jonathan shared with VOA’s Hausa Service audio from a phone call Jonathan made to president-elect Muhammadu Buhari that revealed how he conceded defeat after Saturday and Sunday's presidential election voting.

Jonathan also congratulated the winner and invited him to a meeting on power transition.

Jonathan: You should find one of these days to come, so that we can sort out how to plan the transitional period.

Buhari: Right, your excellency. Thank you very much.

Jonathan: OK, congratulations.

Buhari: My respect, your excellency. Thank you.

Jonathan, of the Peoples Democratic Party, lost to former head of state Buhari, of the All Progressives Congress, in the March 28-29 vote. It was the first time an incumbent president had lost a re-election bid in Nigeria.

According to analysts, "Graciously conceding defeat is not something candidates in African elections have traditionally been very good at," but a growing number are doing it.

Buhari is to take control of Africa’s most populous country and biggest economy on May 29. Nigeria is facing economic decline because of falling oil prices and the Boko Haram insurgency in the northeastern part of the country.

The Islamic extremist group kidnapped more than 270 schoolgirls from Chibok town in Nigeria’s northeast last April. About 50 escaped, but most have yet to be found.